Technical Field
The present disclosure generally pertains to optical test instruments and evaluating optical communication links.
Description of the Related Art
Optical communication links, such as fiber optic cables, provide high speed transmission of data with relatively low loss. In view of this, optical communication links are often used in telecommunication networks, such as telephone lines, cable systems and the internet. In order to allow for adjustments to a network, such as adding, dropping, or moving optical cables in the network, or for coupling and decoupling to various transmitting and receiving equipment, each end of the fiber optic cables is held by a connector, such as a ceramic ferrule, a bulkhead adapter in a patch panel, etc., that allows for coupling and decoupling of the fiber optic cables. The connectors are designed to align endfaces of two fiber optic cables to be coupled, and to abut the endfaces of the optical fibers of the fiber optic cables in physical contact with each other. The connectors also allow the endfaces of the fiber optic cables to be aligned with optical inputs and outputs of various transmitting and receiving equipment.
Performance of the fiber optic cables is affected by the integrity of the fiber optic cables and the quality of the connection between abutting fibers or other optical connections. Prior to coupling, various tests may be performed on fiber optic cables to confirm that the cable satisfies appropriate standards. For instance, a power test may be conducted to evaluate the amount of power or power loss in a transmitted optical signal. Additionally, contamination between abutting optical fibers of two abutting fiber optic cables may block, diffuse, or misdirect the optical signal traveling from one optical fiber to another abutting optical fiber, thereby affecting the output signal. Thus, another test involves a visual inspection of endfaces of the fiber optic cables to confirm the cleanliness of the endfaces of the optical fibers of the fiber optic cables prior to coupling.
A visual inspection process typically involves a fiber optic inspection scope that illuminates an endface of optical fibers of a fiber optic cable and obtains images of the endface. The inspection process may include a comparison to endface goodness standards for the intended application of the fiber optic cable. Such standards may be set by the International Electrotechnical Commission (IEC) (e.g., IEC Standard 61300-3-35) or various other organizations that set forth objective requirements for optical communication links, including Telecommunications Industry Association (TIA), Technical Standard Board (TSB), International Organization for Standardization (ISO), and Institute of Electrical and Electronic Engineers (IEEE).